Couplings for the detachable connection of a fiber-optical light guide to a coupling counterpart are known. Thus, for example, couplings for connecting an optical fiber cable to a coupling counterpart constructed as the light connection of an endoscope are known. Here, illuminating light is generated in a light source separate from the endoscope and coupled into a fiber-optical light guide that can consist of a plurality of optical fibers. The fiber-optical light guide is part of an optical fiber cable that can be connected to the light source and to an endoscope and comprises a coupling for this. The optical fiber cable can be connected to the light connection of the endoscope in order to couple the illuminating light into another fiber-optical light guide arranged inside the endoscope in order to forward the illuminating light to an object field to be observed that is as a rule a hollow space inside the body. The fiber-optical light guide of the optical fiber cable as well as the one inside the endoscope customarily comprise to this end planar end surfaces that are brought in contact with one another or into an opposing position for transmitting the illuminating light, whereby an air gap can also remain between the end surfaces.
It is necessary when using the endoscope to establish a secure connection between the optical fiber cable and the endoscope. If the connection is detached in an unintended manner, not only is the endoscopic observation of the hollow space inside the body interrupted but also the very bright illuminating light can result in burns upon an uncontrolled movement of the free end of the optical fiber cable. Since both can result in disadvantageous or even dangerous situations in an endoscopic operation, it is important to avoid an unattended detachment of the connection. On the other hand, the connection of the optical fiber cable to the endoscope should always be able to be closed in a rapid and simple manner and detached again in order that a rapid and reliable establishing and detaching of the connection is possible in an operation situation without all too great attention being required from an operating person. It is therefore necessary, in particular in medical usages, to make possible a simple and reliable connecting and detaching of a fiber-optical light guide from a counterpart.
Therefore, couplings with a lock connection have been developed in which an unintended detaching of the connection of a fiber-optical light guide from a light connection should be avoided. An optical waveguide plug is known from DE 93 14 172 U1 in which a gripping casing is arranged in such a manner that it can be axially shifted relative to a plug body in which body a plug pin that surrounds an LW L fiber is guided in such a manner that it is secured against rotation but can axially shift. In order to increase the resistance of the plug to being pulled out, locking hooks are provided that engage into a circumferential groove of a coupling casing. A lifting device for lifting the locking hooks out and for a simple pulling of the plug can be activated by axially shifting the gripping casing. According to DE 10 2004 009 218 B4 a locking device is provided in a coupling connection of a fiber-optical light guide coupling cable with an endoscope lens, whereby a radially movable locking body engages in a recess on the circumference of a connection piece. A gripping casing supported in a longitudinally shiftable manner carries an inwardly projecting cam that holds the locking body in the locking position in the rest position of the gripping casing. By shifting the gripping casing in the longitudinal direction the locking body is released so that the fiber-optical light guide connection cable can be plugged in and pulled off.